|No, this is not a flamebait, hear me out.|
Since I got the iPhone X I have noticed that when I would watch movies in bed at night, I would wake up with sore eyes that would eventually turn into headaches.
Searching the web I found a lot of people complaining about the PWM on the iPhone X, and I got convinced that it was the screen that was causing my eye strain, so stopped using the X.
Until I got the XR a few days ago. As usual I watched some Netflix while in bed before falling asleep and woke up with the all so familiar sore eyes. This meant that all this time it was not the OLED the one responsible for my headaches, but something else. The only other think that was new both in X and XR was the FaceID.
I started thinking how can it cause problems and came with the theory below. When I am at bed the room is really dark and so I set the brightness level on my iPhone to the lowest setting. My eye-pupils are fully dilated to adjust to the lack of light. My theory is that the FaceID illuminator doesn't take into consideration the amount of light in the environment and uses the same intensity as if it was daylight.
To prove this I took a recording of my iPhone X in similar environment with an IR camera: https://youtu.be/7ewR9wUjnsc
If this wasn't IR but visible light it would be like the iPhone's camera flash going on every 5 seconds right in front of my eyes. There is no question that this would justify the morning soreness and headaches.
My question is: Does the IR light emitted by the iPhone "flood illuminator" have the same effect to my retina even thought I don't perceive it?